Example 2.1.2: Membrane diffusion Derive the concentration profile and the flux for a single solute diffusing across a thin membrane. The analysis is the same as before leading to ()212zz1z1dzcdDjjA0=−=∆+but the boundary conditions differ: 11101Hcc,zHcc,0z====where H is a partition coefficient(the concentration in the membrane divided by that in the adjacent solution e.g. Henry’s or Raoult’s law). Then the concentration profile becomes: ()zccHHcc101101−+=10c1c10c1cThe solute is moresoluble in the membrane than in the adjacent solution The solute is lesssoluble in the membrane than in the adjacent solution

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